Swing-arm clamps are commonly known in the art. They are characterized by their clamping arm which not only extends and retracts, but also rotates or otherwise moves askew of the extending or retracting movement. Such clamps are typically used in assembly lines or other work environments where the swing-arm clamp engages and secures a workpiece to secure the same in place while some operation is conducted thereon. These clamps are useful in that they have the ability to not only clamp and release the workpiece, but the clamp can also move clear of the workpiece so it can be moved.
Examples of such clamps are found, for example, in U.S. Pat. Nos. 5,437,440 and 6,435,493 B1, the disclosures of which are herein incorporated by reference.
Because such clamps operate in assembly line or like environments, they are susceptible to damage. The dynamic nature of such conditions, where large, heavy workpieces and parts are being repeatedly moved, stamped or welded together, create virtually limitless opportunities for these clamps to become damaged. The repetition of clamping and releasing workpieces may cause a “backlash” on the clamp which can wear parts and eventually impair or otherwise damage the clamp. For example, typical swing-arm clamps have a bearing or other similar member attached to either the piston rod or the piston that engages a winding cam track. It is the bearing following the cam track that causes the arm attached to the piston rod to swing or move askew while the rod is extending and retracting. Typically, when the piston rod retracts and clamps down onto a workpiece, the resulting forces are referred to as “backlash.” This “backlash” transfers force into the bearing and cam track. The constant repetition of the swing-arm clamp extending and releasing is what may cause the wear between the bearing and cam track. This is unless the “backlash” can be transferred to another structure that will relieve the bearing and the cam track. It would, thus, be beneficial to provide such structure, or structures.
Another potential hazard for such swing-arm clamps is weld splatter. The splatter is produced while workpieces are being joined and welded together during an assembly operation, for example. Because the clamp arm extends and retracts between release and clamp positions, the piston rod, which produces the extension and retraction, is often, at least partially, exposed. Weld splatter might deposit onto the exposed portion of the piston rod, cool, harden, and prevent the piston rod from properly extending and retracting. This, consequently, prevents the clamp arm from clamping or releasing the workpiece. It would therefore be beneficial to provide a shield to protect the piston rod from weld splatter or the like.
Accordingly, a swing-arm clamp may be provided which comprises an actuator, a piston, a body, a piston rod, an arm, a guide, and a locating member. The piston is movable within the body in response to the actuator. The piston rod is located within the body and extends from the piston. In addition, the piston rod is movable through the body in response to movement by the piston along a longitudinal axis between first and second positions. The piston rod is also movable about the longitudinal axis as it is movable along the longitudinal axis. The arm is attached to the piston rod, being movable both along the longitudinal axis between the first and second positions, and about the longitudinal axis. The locating member is movable in concert with the piston rod. The locating member also engages the guide when the arm is located in the first position and separates from the guide when in the second position.
In the above-described and other embodiments, the swing-arm clamp may comprise: a first position of the arm and piston rod being a clamping retracted position; a second position being the releasing extended position; a guide being attached to the body; the guide being adjustable with respect to the body; a plug attachable to the body and movable with respect thereto; the plug being selectively positionable to affect the positioning of the piston rod about the longitudinal axis at the first and second positions; the plug being selectively locked in a desired position; the plug being located in a bore in the body; the plug having a threaded periphery that is engagable with a threaded periphery on the bore; the plug having a set that secures the plug in a desired position; the plug having a spline disposed therein and the set being a fastener disposed in the plug and engagable with the spline such that engagement of the spline secures the plug in the desired position; the spline of the plug is disposed in the plug's threaded periphery; a locating member being attached to the arm; a shield that shrouds the piston rod when the same is in its first position; a locating pin being attached to the shield; and the locating pin being an angled member, one end of which extends into the guide when the piston rod is located in the first position.
Another illustrative embodiment provides a swing-arm clamp which comprises an actuator, a body, a rod, a clamp and a shield. The rod is disposed in the body and is movable longitudinally in response to the actuator. The rod is also rotatable with respect to its longitudinal movement. In addition, the rod is at least partially extendable from the body. The clamp arm is attached to the rod. The shield at least partially obscures at least a portion of the rod that is at least partially extended from the body.
In the above-described and other embodiments, the swing-arm clamp may comprise: a rod being movable between first and second positions; a shield obscuring a portion of a rod that is extended from a body when the rod is in the first position; the shield being located adjacent a clamp arm; and a locating member attached to the clamp that is engagable with a guide member which is also attached to the clamp.
Another illustrative embodiment provides a swing-arm clamp which comprises a body, a piston assembly, a cam member, and a base. The piston assembly is disposed in the body and is movable longitudinally with respect to the body. The cam member has a camming surface disposed therein which is in communication with the piston assembly to cause movement of same askew of its longitudinal movement. The base is attached to the cam member and is selectively movable to affect the askew movement of the piston assembly.
In the above-described and other embodiments, the swing-arm clamp may comprise: a base having a lock that will selectively maintain the base at a desired position; the lock being a fastener; a base being located in a bore disposed in a body; a base having a threaded periphery that is engagable with a corresponding threaded periphery of a bore. A base having a spline disposed therein, wherein a fastener is engagable with the spline such that engagement of the spline by the fastener secures a plug in a desired position; the spline of the base is disposed in the threaded periphery of the base.
Another illustrative embodiment provides a swing-arm clamp having a rod extending from a body. The rod is movable along a longitudinal axis and is movable through the body between clamping and releasing positions. The rod is also movable about the longitudinal axis. The swing-arm clamp also comprises a means for absorbing force caused from backlash created as the swing-arm clamp clamps a workpiece.
Another illustrative embodiment provides a swing-arm clamp having a rod extending from a body. The rod is movable through the body along a longitudinal axis between a clamping position and a releasing position. The rod is also movable about the longitudinal axis. A shroud is located adjacent the piston rod to obscure at least a portion of the same when the piston rod is in the clamping position.
Additional features and advantages of the swing-arm clamp will become apparent to those skilled in the art upon consideration of the following detailed description of the illustrated embodiment exemplifying the best mode of carrying out the swing-arm clamp as presently perceived.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplification set out herein illustrates embodiments of the swing-arm clamp, and such exemplification is not to be construed as limiting the scope of the swing-arm clamp in any manner.